Microencapsulation of Lactobacillus casei by spray drying

Abstract

This study evaluates the use of spray drying to produce microparticles of Lactobacillus casei. Microorganism was cultivated in shaken flasks and the microencapsulation process was performed using a laboratory-scale spray dryer. A rotational central composite design was employed to optimise the drying conditions. High cell viability (1.1 × 10¹⁰ CFU/g) was achieved using an inlet air temperature of 70 °C and 25% (w/v) of maltodextrin. Microparticles presented values of solubility, wettability, water activity, hygroscopicity and humidity corresponding to 97.03 ± 0.04%, 100% (in 1.16 min), 0.14 ± 0.0, 35.20 g H₂O/100 g and 4.80 ± 0.43%, respectively. The microparticles were spherical with a smooth surface and thermally stable. Encapsulation improved the survival of L. casei during storage. After 60 days, the samples stored at −8 °C showed viable cell concentrations of 1.0 × 10⁹ CFU/g.

• Experimental planning
• maltodextrin
• microparticles
• probiotic

Acknowledgments

Gratitude must go to Dr Luciano Bueno (Rural Federal University of Pernambuco, Brazil) for technical assistance during the thermal analysis, and Rafael Albuquerque for the assistance during microscopic analysis.